To explore the relationship between physical activity and sleep quality of college students based on the mediating effect of stress and subjective well-being

Abstract

Promoting the physical and mental health of college students is an inevitable requirement of the global health perspective. Given the close relationship between physical activity, sleep, and mental health, this study explores the mediating role of mental health in the relationship between physical activity and sleep quality. A cross-sectional study was conducted among 4,706 college students, who self-reported their levels of physical activity, stress, subjective well-being, and sleep quality. The results showed that physical activity significantly and positively predicted sleep quality (β = 0.106, SE = 0.016, p < 0.001), and this positive predictive effect remained significant after the inclusion of mediating variables (β = 0.072, SE = 0.013, p < 0.001). Stress and subjective well-being acted as mediating factors between physical activity and sleep quality, forming a chain mediation effect. This study reveals the multiple benefits of physical activity for the development of college students and suggests that society, schools, families, and individuals should actively explore ways and means to engage in physical activity and exercise regularly. Future research is recommended to investigate the longitudinal changes in mental health between physical activity and sleep quality.

Introduction

While the importance of physical activity and sleep for health has been widely recognized [1–3], understanding the complex and underlying mechanisms between them is crucial for designing more effective health intervention programs. As a key factor in promoting health and enhancing quality of life, physical activity has been extensively evidenced to exert broad benefits on both physical and psychological well-being, serving as a potentially effective means to improve sleep [4–8]. Building on theoretical models from existing studies [9–11]—such as the energy conservation theory, restoration theory, and brain plasticity theory—we can gain multifaceted insights into the close relationship between physical activity and sleep quality.

Numerous potential variables may influence the relationship between physical activity and sleep quality, with negative emotions being among them [12–14]. This study selected stress and subjective well-being as mediating variables, as they represent the primary psychological pathways through which physical activity may impact sleep: one pathway involves alleviating negative emotions (stress), and the other involves enhancing positive emotions (subjective well-being). Together, these two pathways form complementary perspectives on how physical activity improves sleep quality through psychological mechanisms. The present study aims to propose a chain mediation model to reveal the intrinsic psychological mechanisms underlying the improvement of sleep quality through physical activity, and to explore the significant roles of stress and subjective well-being in this relationship.

Physical activity and sleep quality

Physical activity, as an essential component of global health development, refers to any bodily movement produced by skeletal muscles that results in energy expenditure [15]. It plays a crucial role in human health and quality of life. Physical activity has multiple benefits, including the improvement of chronic diseases, reduction of disease risk, enhancement of physical fitness, and promotion of mental health [16–23]. Despite the widely acknowledged value of physical activity, insufficient physical activity remains a significant challenge to global health. Large-scale demographic surveys indicate that insufficient physical activity is on the rise among adolescents and adults. A meta-analysis of longitudinal cohort studies investigating changes in physical activity from adolescence to adulthood indicated a slight decline in physical activity between adolescence and young adulthood [24]. Additionally, studies using accelerometers have demonstrated a decrease in vigorous physical activity (VPA) during this transition [25]. Therefore, focusing on physical activity during the college years is crucial, as it facilitates the sustainable development of physical and mental health.

A notable feature of college students’ lifestyles is not only insufficient physical activity but also poor sleep quality [26]. The National Institute of Neurological Disorders and Stroke (NINDS) emphasizes that sleep, like food and water, is a vital component of daily life, affecting various body tissues and systems, including brain function [27]. Therefore, good sleep quality is an integral part of a healthy lifestyle. Sleep quality is defined as an individual’s satisfaction with their sleep experience, encompassing sleep efficiency, sleep latency, sleep duration, and awakenings after sleep onset [28, 29]. Numerous studies have demonstrated the benefits of good sleep quality, which is associated with bone function, cardiovascular diseases, mortality risk, executive function, mental health, and social relationships [2, 30–33]. The importance of sleep quality has been validated across different populations, including college students [34, 35]. It is imperative to actively monitor the physical activity and sleep quality of college students to promote their sustainable physical and mental health development.

The relationship between physical activity and sleep quality

Among the many benefits of physical activity, its role in improving sleep has been empirically confirmed [36, 37]. A meta-analysis of 23 studies showed a positive correlation between physical activity and sleep quality, with sports activities alleviating the severity of insomnia and other sleep disorders [4]. Numerous empirical studies have also demonstrated the relationship between physical activity and sleep quality. For example, higher levels of physical activity (β = -0.007, 95% CI [-0.013, -0.001], p < 0.05) and moderate levels of physical activity (β = -0.013, 95% CI [-0.022, -0.003], p < 0.05) are associated with better sleep quality [38]. Various theories have provided support and explanations for the relationship between physical activity and sleep quality. The energy conservation theory [11] posits that the energy expenditure during physical activity necessitates the repair and replenishment of muscles, tissues, and hormones during sleep. The thermoregulation theory [10] suggests that the central networks controlling sleep and body temperature regulation overlap, and the impact of physical activity on body temperature also affects sleep. The hormone regulation theory [9] indicates that physical exercise influences the secretion of melatonin, a natural supplement for sleep regulation. This study focuses on the relationship between physical activity and sleep quality, aiming to elucidate the underlying mechanisms of their interaction.

The mediating role of stress between physical activity and sleep quality

Stress can be defined as a state of worry or mental tension caused by difficult situations [39]. It is also understood as a condition of physical, mental, or emotional strain or tension that leads to restlessness, worry, and sleep deprivation [40]. Healthy sleep is crucial for the physical and mental development of college students, and stress is one of the factors contributing to poor sleep quality among this population [41, 42]. Previous research has demonstrated a significant correlation between stress and sleep quality [43]. Similarly, physical activity is closely related to stress. Empirical studies have shown that physical activity can buffer the negative association between psychological stress and emotional health [44]. The cross-stressor adaptation hypothesis [45, 46] suggests that individuals who engage in physical exercise exhibit lower physiological and psychological responses to stressors outside of exercise. This hypothesis provides theoretical support for the notion that physical activity can maintain mental health by reducing stress. In existing research, the role of stress between physical activity and sleep has garnered attention. For example, stress has been shown to mediate the relationship between physical activity and insomnia [47], as well as between physical activity and sleep quality [48]. Based on the relationships between stress, physical activity, and sleep quality, it can be further inferred that reducing stress levels through physical activity can contribute to the improvement and enhancement of sleep quality.

The mediating role of subjective well-being between physical activity and sleep quality

Subjective well-being refers to an individual’s perception that their life is desirable, regardless of how others may view it [49]. The scope of subjective well-being is broad, encompassing cognitive and emotional aspects, and includes various dimensions of life satisfaction and emotional experiences [50]. Subjective well-being is influenced by numerous factors, such as education, marital status, social interactions, and health status [51, 52]. Particularly, health status is a significant factor. A meta-analysis of 29 studies showed a significant positive correlation between health status and subjective well-being (r = 0.347, 95% CI = 0.309-0.385, P < 0.001) [53]. As an essential component of a healthy lifestyle, physical activity is closely related to subjective well-being. A random-effects meta-analysis using robust variance estimation showed a significant positive correlation between physical activity and subjective well-being (d = 0.360, 95% CI [0.301, 0.420]) [54]. Numerous studies have confirmed that various forms and intensities of physical activity are closely linked to subjective well-being [55–58], and this relationship has been validated among college students [59]. Sleep quality, as another component of a healthy lifestyle, is also closely related to subjective well-being [60–63]. Based on the relationships between subjective well-being, physical activity, and sleep quality, it is hypothesized that subjective well-being mediates the relationship between physical activity and sleep quality, thereby exploring the mechanism through which physical activity affects sleep quality.

The relationship between stress and subjective well-being

Subjective well-being encompasses cognitive and emotional aspects. Both perceived stress and stress-induced emotional issues reflect the correlation between subjective well-being and stress. Previous research has shown a close relationship between negative emotions and subjective well-being, such as anxiety, depression, and stress [64, 65]. Studies have proposed a significant negative correlation between perceived stress and subjective well-being [66]. A large-scale study demonstrated the universal association between stress, a negative emotion, and subjective well-being [67]. This correlation has also been validated among college students in different regions [68, 69]. Therefore, it is inferred that stress and subjective well-being act as a chain mediator between physical activity and sleep quality.

Research hypotheses and model

Based on the existing literature, to verify the mechanism of action between physical activity and sleep quality, propose a theoretical model (Fig. 1) and the following research hypotheses are proposed: H1: Physical activity, sleep quality, stress, and subjective well-being are significantly and positively correlated. H2: Stress mediates the relationship between physical activity and sleep quality. H3: Subjective well-being mediates the relationship between physical activity and sleep quality. H4: Stress and subjective well-being act as a chain mediator between physical activity and sleep quality.This study focuses on the relationship between physical activity, sleep quality, and mental health. It aims to elucidate how physical activity affects sleep quality from a psychological perspective and provide effective solutions for addressing issues related to mental health and sleep quality among college students based on the research findings.

Fig. 1.

Research model diagram

Methods

Participants

A total of 4,142 college students were recruited from universities in Hunan, Sichuan, Guangdong, Fujian, and other regions. After data cleaning, 4,076 valid questionnaires remained, yielding an effective response rate of 98%. The participants had an average age of 19.04 ± 1.154 years, including 1,502 males and 2,574 females. Among them, 1,028 were only children and 3,048 had siblings. A convenience sampling method was used, with questionnaires administered electronically by teachers before class. The inclusion criteria for the study were as follows: being part of the college student population, completing all items of the scale, demonstrating no pattern of regular responding, and having a response time of 1 to 3 min (this range was determined by referencing the completion times of 52 college students recruited prior to the formal measurement). The study protocol was approved by the Biomedical Ethics Committee of Jishou University (JSDX 2024 0086). All participants provided written informed consent, and their data were strictly confidential. Participants had the right to withdraw from the study at any time.

Measurement tools

Data on physical activity, sleep quality, stress, and subjective well-being were collected using single-item questionnaires, all of which have been widely utilized in existing research. Single-item measurements have gradually gained acceptance in psychological research, offering advantages such as reducing research costs, improving research efficiency, enhancing participants’ willingness to complete the surveys, and being suitable for large-sample studies. Based on discussions regarding the feasibility of single-item measurements [70, 71], representative and widely used single-item questionnaires were selected for data collection.

Physical activity

Physical activity was assessed using a single-item measure [72], which asked participants, “How many days in the past 7 days did you exercise or engage in at least 20 minutes of physical activity that made you sweat or breathe hard?” Responses ranged from 0 to 7 days, with higher values indicating higher levels of physical activity. This scale has been widely used in physical activity research [73–79] and has demonstrated good reliability and validity.

Sleep quality

Sleep quality was evaluated using a single-item measure [80] that assessed overall sleep quality based on the following aspects: sleep duration, difficulty falling asleep, frequency of waking up during the night (excluding bathroom visits), frequency of waking up earlier than necessary in the morning, and overall mental state upon waking. The scale ranged from 1 to 10 points, with higher scores indicating better sleep quality. This measure has been validated cross-culturally [81] and has been used among college students [82].

Stress

Stress levels were measured using a single-item stress symptom scale [83], which asked participants, “Do you feel tense, restless, nervous, or anxious, or have trouble sleeping at night because of constant worrying?” Responses were rated on a 4-point Likert scale ranging from 1 (not at all) to 4 (very often), with higher scores indicating higher levels of stress. This scale has been used in numerous studies [84] and provides a feasible measure for this study.

Subjective well-being

Subjective well-being was assessed using a single-item measure [85, 86], which asked participants to rate their current level of happiness on a 7-point Likert scale ranging from 1 (very dissatisfied) to 7 (very satisfied). Higher scores indicated higher levels of subjective well-being. This measure has been validated cross-culturally and is suitable for use across different populations.

Data analysis

Data were analyzed using SPSS version 26.0. First, common method bias was assessed using Harman’s single-factor test, ensuring that the bias was within an acceptable range (less than 40%). Next, descriptive statistics and correlation analyses were conducted after standardizing the main variables. Finally, to test our hypotheses, we used Model 6 in the PROCESS V4.1 macro for SPSS [87] to examine the relationship between physical activity and sleep quality, as well as the mediating roles of subjective well-being and stress. We employed 5,000 bootstrap resampling iterations to assess model fit and estimate 95% confidence intervals (95% CI) [88], ensuring robustness in our analyses. Gender, age, grade, and only-child status were controlled as covariates in the analyses. The significance level was set at 0.05.

Results

Common method bias test

The Harman single-factor test was employed to assess common method bias in this study [89]. The results indicated the presence of four factors with eigenvalues greater than 1. The first factor accounted for 19.95% of the total variance, which is below the 40% threshold. This suggests that there is no significant common method bias in this study.

Correlation analysis

Table 1 presents the results of the correlation analysis. Physical activity was significantly and positively correlated with sleep quality (r = 0.104, p < 0.001) and subjective well-being (r = 0.065, p < 0.001), and significantly and negatively correlated with stress (r = -0.047, p < 0.01). Sleep quality was significantly and positively correlated with subjective well-being (r = 0.398, p < 0.001) and significantly and negatively correlated with stress (r = -0.507, p < 0.001). Subjective well-being was significantly and negatively correlated with stress (r = -0.342, p < 0.001).

Table 1.

Correlation analysis

Variables	1	2	3	4
1 PA	-
2 SQ	0.104***	-
3 Stress	−0.047**	−0.507***	-
4 SWB	0.065***	0.398***	−0.342***	-
M	3.11	7.09	1.57	5.07
SD	0.03	0.03	0.01	0.22

Note: **: p<0.01; ***: p<0.001; PA = Physical activity; SQ = Sleep quality; SWB = Subjective well-being

Mediation effect analysis

The results of the mediating effect test (Tables 2 and 3, and Fig. 2) showed that physical activity directly and significantly positively predicted sleep quality (β = 0.106, SE = 0.016, p < 0.001). When analyzing the indirect effects, physical activity remained a significant predictor of sleep quality (β = 0.072, SE = 0.013, p < 0.001). Physical activity significantly and negatively predicted stress (β = -0.040, SE = 0.016, p < 0.05) and significantly and positively predicted subjective well-being (β = 0.058, SE = 0.015, p < 0.001). Stress significantly and negatively predicted subjective well-being (β = -0.341, SE = 0.015, p < 0.001) and significantly and negatively predicted sleep quality (β = -0.418, SE = 0.014, p < 0.001). Subjective well-being significantly and positively predicted sleep quality (β = 0.249, SE = 0.014, p < 0.001). The total indirect effect accounted for 33.02% of the total association (95% CI [0.017, 0.052]). Decomposition of specific mediation pathways revealed: the stress-only pathway (PA → Stress → SQ) explained 16.04% of the total effect; the subjective well-being-only pathway (PA → SWB → SQ) contributed 13.21%; the serial mediation pathway (PA → Stress → SWB → SQ) accounted for 2.83% of the total effect.

Table 2.

Chain mediation model test

Outcome Variable	Predictor Variable	β	SE	t	R 2	F
SQ	PA	0.106	0.016	6.638***	0.016	9.180***
Stress	PA	−0.040	0.016	−2.512*	0.013	7.467***
SWB	PA	0.058	0.015	3.808***	0.122	70.789***
	Stress	−0.341	0.015	−23.080***
SQ	PA	0.072	0.013	5.421***	0.320	212.732***
	Stress	−0.418	0.014	−30.207***
	SWB	0.249	0.014	18.073***

Note: *: p < 0.05; **: p < 0.01; ***: p < 0.001; PA = Physical activity; SWB = Subjective well-being; SQ = Sleep quality

Table 3.

Path analysis of the chain mediation model

Mediating Path	Effect	SE	Bootstrap 95% CI	Proportion of Mediated Effect
Total Effect	0.106	0.016	0.075, 0.137
Direct Effect	0.072	0.013	0.045, 0.098
Total Indirect Effect	0.035	0.009	0.017, 0.052	33.02%
PA→Stress→SQ	0.017	0.007	0.003, 0.030	16.04%
PA→SWB→SQ	0.014	0.004	0.006, 0.023	13.21%
PA→Stress→SWB→SQ	0.003	0.001	0.001, 0.006	2.83%

Note: PA = Physical activity; SWB = Subjective well-being; SQ = Sleep quality

Fig. 2.

Mediation model diagram

Note: ***: p < 0.001

Discussion and analysis

This study confirmed the correlations between physical activity, sleep quality, stress, and subjective well-being, and elucidated the mechanism through which physical activity benefits sleep quality via the chain mediation of stress and subjective well-being. The findings highlight the positive impact of physical activity on improving lifestyle and enhancing quality of life, and encourage college students to engage in physical activities and exercise regularly.

The positive correlation between physical activity and sleep quality is consistent with previous research findings [4, 90], which have also been widely validated among college students [12, 91]. The study found that physical activity directly and significantly influenced sleep quality, and even after including mediating variables, physical activity still significantly and positively predicted sleep quality, albeit with a reduced effect size. Numerous studies have examined the impact of different types and intensities of physical activity on sleep quality [36, 92], but the results have not been uniform, likely due to the combined influence of region, participants, and other factors. The theoretical explanations for the relationship between physical activity and sleep quality include physiological mechanisms such as growth hormone [93], cytokines [84], and thermoregulation [10], which provide a multifaceted explanation for their relationship and strengthen the existing evidence.

Stress mediates the relationship between physical activity and sleep quality, consistent with previous findings [47, 48]. In the factors influencing sleep quality, emotional regulation holds significant value [95, 96]. Existing research has demonstrated that physical activity can indirectly predict sleep quality through emotional regulation [97]. Stress is frequently associated with sleep quality, insomnia, and sleep disorders among college students [41, 42, 98]. College students face multiple pressures from academics, daily life, and social interactions, and physical activity can improve sleep by enhancing stress coping [13]. The mechanisms through which physical activity alleviates stress include not only physiological aspects such as monoamine metabolism and endorphin release [99, 100], but also psychological mechanisms like the distraction hypothesis [99], self-expansion theory [101], and social interaction hypothesis [102], providing theoretical guidance and support for the mediating role of stress.

Subjective well-being also mediates the relationship between physical activity and sleep quality. The strong connection between physical activity and subjective well-being is based on positive psychology, which emphasizes understanding the processes and factors that contribute to personal health, success, and flourishing [103]. As one of the ways to benefit personal health, physical activity has established a potential link with subjective well-being [104]. Numerous empirical studies have shown a significant positive correlation between physical activity and subjective well-being [52, 61], which has been validated across different populations, types of exercise, intensities, and durations [57, 62, 90, 97, 105]. Research has also shown that sleep significantly and positively predicts subjective well-being [60–63]. Our study found that subjective well-being significantly and positively predicts sleep quality. The empirical evidence of the bidirectional relationship between subjective well-being and sleep quality may be influenced by structural definitions and measurement heterogeneity [106].

Most studies have shown a significant negative correlation between stress in different contexts (work, academics) and subjective well-being [90, 107], with no differences across countries and regions [68, 98, 107, 108]. In the PERMA model of subjective well-being, positive emotion is a key component [109, 110], which has been empirically validated. Stress, as a form of negative emotion, is inversely related to subjective well-being. Emotional theories, which emphasize that positive/negative emotions are direct/indirect factors of subjective well-being [111], also provide strong theoretical support for this study.

By constructing a chain mediation model of physical activity and sleep quality, this study verified the progressive pathway of physical and mental health development in the field of exercise and health, addressing the limitations of traditional single mediation models in analyzing the dynamic associations of psychological mechanisms. The chain mediation model revealed the mechanism pathway of “physical activity-emotional improvement-sleep optimization,” which not only provides a theoretical basis for physical activity to promote physical and mental health development, but also offers directions for the implementation and intervention of college students’ physical activity. The findings regarding the serial role of emotional health between physical activity and sleep quality help us pay active attention to psychological variables such as stress coping, subjective well-being, psychological resilience, resilience, social support, and life satisfaction when addressing college students’ sleep problems. This provides a new perspective for understanding the synergistic mechanism of “exercise-emotion-health.” When dealing with college students’ sleep issues, a stepwise intervention strategy (first reducing stress and then enhancing well-being) can be adopted. Future studies are suggested to refine exercise intervention programs and explore issues related to the periodicity and timeliness of physical activity. Additionally, it is recommended to supplement demographic variables such as family relationships and family economic status, as well as other emotional variables, to further reveal the mechanisms at a micro level.

This study has several limitations. First, limitations in the sampling method. Data were collected and analyzed using convenience sampling, which cannot objectively reflect the overall status of all research populations and may have biases related to region, culture, and environment. Second, limitations in the sample size. This study focused on college students, with participants recruited from selected regions. Future research should expand the scope to conduct large-scale and wide-ranging investigations. Third, the singularity of cross-sectional research. This study used self-reported data from participants in a cross-sectional survey to explore correlations and mediating effects among variables, but it cannot infer causality. Future studies are recommended to conduct cohort follow-up research over time to verify the benefits of physical activity. Fourth, the limitation of relevant variables. Physical activity, sleep quality, and mental health are closely linked, and mental health involves a wide range of related variables. Variables such as depression, anxiety, psychological resilience, and social support were not included in this study beyond the selected ones. Future research should enrich the variable content and model structure. Fifth, limitations of the measurement tools. Physical activity, sleep quality, stress, and subjective well-being were all assessed using single-item measures. While these measures offer advantages such as reducing research costs and improving research efficiency, they lack validation against objective statistical criteria and are susceptible to measurement errors. Therefore, it is necessary to strengthen research design (particularly regarding measurement tools) in future studies to ensure research quality.

Conclusions

This study confirmed the relationship between physical activity, sleep quality, and mental health and explored the chain mediation role of stress and subjective well-being between physical activity and sleep quality among college students. It further revealed the dual benefits and mechanisms of physical activity among college students. Promoting various forms of physical exercise interventions, such as school sports, community sports, and family sports, can facilitate the comprehensive development of college students. Future research is recommended to conduct cross-cultural cohort studies to explore and explain causal relationships.

Author contributions

Jinling Yin123456, Xiaolei Chen2356, Zhenxiu Yi12345, Liping Deng1235, Yang Liu12345. 1 Conceptualization; 2 Methodology; 3 Data curation; 4 Writing - Original Draft; 5 Writing - Review & Editing; 6 Funding acquisition.

Funding

Not applicable.

Data availability

The datasets generated and/or analysed during the current study are not publicly available due [our experimental team’s policy] but are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by the Biomedicine Ethics Committee of Jishou University before the initiation of the project (Grant number: JSDX-2024-0086). Informed consent was obtained from the participants before the start of the program. The study was conducted in accordance with the Declaration of Helsinki.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.